In many areas of technology, apparatus or devices are used that contain a monitor activating means, by means of which the apparatus or devices can display various data such as, for example, operating parameters, measured values, help texts, or alarm messages on a monitor connected to the monitor activating means. The monitor activating means frequently includes a suitably programmed microprocessor and a graphics controller coupled to this. An example of such apparatus or devices are machine controls, which display on a monitor, among other things, operating parameters of the machine, control parameters and measured values.
Another example are technical apparatus which are used in the area of anesthesia and which support the anesthesiologist in his work and which make the anesthesia safer for the patient. Anesthesia apparatus of this type provide not only functions for the accurately dosed supply of narcotics and other medications in the body of the patient, but also functions for monitoring and maintaining the various vital functions of the patient, such as, for example, oxygen supply, circulatory function and breathing. The anesthesia apparatus usually have a monitor activating means with a microprocessor that has been suitably programmed and a graphics controller coupled to this, so that the anesthesia apparatus is able, by means of the microprocessor via the graphics controller, to display apparatus parameters of the anesthesia apparatus, various measured values, which may refer, for example, to the vital functions of the patient or to the amount of narcotics or medications actually supplied, alarm messages and other data on a monitor connected at an output terminal of the graphics controller. These monitors are frequently an integral component of the anesthesia apparatus.
Apparatus and devices of this type, such as, for example, anesthesia apparatus and other medical apparatus, which are used to a large extent in modern medicine, usually have a very high purchase price. In anesthesia apparatus and other apparatus and devices that perform safety-related functions, the high costs are based on the fact that the development is expensive because of the necessary high safety standard and only little savings potential is available in safety-related hardware and software. For this reason, efforts are usually made in practice to use anesthesia apparatus and other apparatus, for example, machine controls over an as long as possible period of time, before they are replaced with newer apparatus. Therefore, many anesthesia apparatus and other apparatus are now still in use, which are designed only for the activation of a monochrome monitor and, correspondingly, are equipped only with a monochrome monitor. In these apparatus, the software and hardware of the monitor activating means or of the microprocessor and of the graphics controller are so limited in their performance and structural design that the activation of a color monitor with a color image signal is impossible. Thus, the microprocessor of a monitor activating means for activating a color monitor with only 256 colors, i.e., with eight bits per image pixel, would already require an eightfold memory space and a considerably higher computing performance than for activating a monochrome monitor with one bit per image pixel, for which it is designed.
Even though the actual dispensing and monitoring functions of anesthesia apparatus themselves are not adversely affected by the use of a monochrome monitor, it has been shown that these functions can be transmitted to the anesthesiologist faster and more reliably by the use of a color visualization of the wide variety of data, some of which are vital. The same also applies to other types of apparatus and devices. In other words, the interface between man and machine can be improved in order to reduce errors. This means not only that a better structuring of the data and a better clarity can be achieved by a color visualization, but also that additional data can be transported by means of colors. Thus, for example, critical measured values or alarm messages can be shown in a color that is different from normal measured values in order to emphasize them on a color monitor and to make them more perceptible for, e.g., the anesthesiologist. Therefore, it is desired in practice to use color monitors and a color visualization of the data advantageously in older anesthesia apparatus and other apparatus and devices as well.
In the state of the art, it has been proposed for anesthesia apparatus to replace the microprocessor and the graphics controller of the monitor activating means of the anesthesia apparatus for this purpose, i.e., to replace these components with a higher-performance microprocessor or with a new or highly revised software and a higher-performance graphics controller, which can generate a suitable color image signal. However, this procedure has the drawback that it entails a high development expense and high costs because of the necessary new hardware and software. In order to keep the costs low and not to take any risk in relation to the application safety, it is generally desirable to make no or only minimal changes to the existing hardware and software.
The same problems also occur in another solution approach from the state of the art, in which the microprocessor of the anesthesia apparatus is equipped with a revised software and is connected to an additional hardware component by circumventing the graphics controller of the anesthesia apparatus, which additional hardware component contains a higher-performance microprocessor and a higher-performance graphics controller. The microprocessor of the anesthesia apparatus with its revised software is, together with the microprocessor of the additional hardware component and the graphics controller of the additional hardware component, powerful enough to activate a color monitor via the graphics controller of the additional hardware component. Even though only the software of the microprocessor has to be changed within the framework of this procedure on the anesthesia apparatus proper, the hardware and software of the additional hardware component are relatively complicated and therefore bring about a high development expense and high costs.